Hermetic Implant Housing Ceramic Frame Thermal Protection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for producing hermetic casings for implantable medical devices face challenges in reducing thickness without compromising mechanical strength, particularly when using thin metal frames, as they can lead to undesirable chemical diffusion and thermal degradation during brazing and welding processes.
Innovation Solution
A method involving a ceramic substrate, a metal frame, and a ceramic frame on the opposite face of the metal frame interface, forming a first hermetic seal by brazing and a second seal by laser welding, with the ceramic frame partially covering the projection surface of the first joint to prevent attachment issues and thermal degradation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If a thin metal frame is used to reduce device volume, then the device can be implanted in more zones and patient comfort is improved, but chemical elements diffuse through the frame during brazing causing undesirable grip on the sample holder
Solution Approach 1:
A ceramic frame is introduced as an intermediary component between the metal frame and the sample holder. This ceramic frame has a projection surface that covers the projection surface of the first hermetic seal, preventing direct contact between the metal frame and the sample holder during brazing. The ceramic material acts as a barrier that stops chemical element diffusion while allowing the brazing process to proceed effectively.
Solution Approach 2:
The invention uses a composite structure combining metal frame, ceramic frame, and hermetic seal materials. This multi-material approach allows each component to perform its specific function: the metal frame provides structural support, the ceramic frame prevents chemical diffusion and grip issues, and the hermetic seal ensures sealing. The combination resolves the contradiction by leveraging the complementary properties of different materials.
2Volume of moving object
If a thin metal frame is used to reduce device volume, then flexibility and patient comfort are improved, but the first hermetic seal may be thermally degraded during laser beam welding
Solution Approach 1:
The first hermetic seal is formed by brazing before the laser beam welding step. The ceramic frame is already in place during brazing, establishing the seal while the metal frame is still intact and providing thermal protection. This preliminary formation of the hermetic seal ensures it is established before any thermal degradation risks from subsequent welding operations.
Solution Approach 2:
The ceramic frame serves as a thermal barrier and intermediary structure during the welding process. Its presence between the laser beam and the first hermetic seal reduces thermal exposure to the seal, preventing degradation while allowing the welding process to proceed. The ceramic material's thermal properties protect the sensitive hermetic seal from excessive heat.
3Reliability
If brazing is performed to form a hermetic seal, then encapsulation is achieved, but chemical elements diffuse through the metal frame causing grip on the sample holder
Solution Approach 1:
The ceramic frame is positioned as an intermediary component during the brazing process. Its projection surface covers the projection surface of the first hermetic seal, creating a physical barrier that prevents chemical elements from diffusing through the metal frame to the sample holder. This intermediary structure allows brazing to proceed while blocking the harmful diffusion path.
Solution Approach 2:
The ceramic frame provides localized protection specifically at the region where chemical diffusion occurs. Rather than modifying the entire metal frame or brazing process, the solution applies a ceramic barrier only where needed - at the interface between the metal frame and sample holder - to prevent grip while maintaining other properties of the system.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables the production of thinner, mechanically flexible hermetic casings that reduce the risk of attachment and thermal degradation, allowing for more precise implantation and improved patient comfort by minimizing the volume of the device.
Implementation Method 1
forming a first hermetic seal at the interface between said substrate and said metal frame, to assemble them and form an assembly, preferably, the first hermetic joint formed during step c) is a brazing joint
Implementation Method 2
forming a second hermetic seal between the face of the metal frame opposite to said interface and the cover to obtain said housing
Data Source
Figure 1A~1D
Figure 2A~2E
Figure 3A~3B
AI summary
A method for producing a hermetic housing comprising the following steps: a) providing a ceramic substrate (20), b) providing a metal frame (21) and placing it opposite said substrate (20), c) forming a first hermetic seal (22) at the interface between said substrate (20) and said metal frame (21), to assemble them and form an assembly, d) superimposing a cover (23) onto said assembly, e) forming a second hermetic seal (24) between an upper face of the metal frame (21) opposite said interface and the cover (23) to obtain said housing, characterized in that, during step c), the first hermetic seal (22) is formed on a portion of said interface and in that, before step c), the method comprises an additional step consisting of placing a ceramic frame (25) on the upper face of the metal frame, so as to partially cover said face of the metal frame,the projection surface of said ceramic frame in a projection plane covering the projection surface of said first joint in that same projection plane.